Things I liked:Given that Gamo usually builds spring guns, they did a GREAT job on this CO2 rifle. Here's what I liked: generally quite, powerful and consistent, good build quality, VERY fun to shoot, pump action is unique and a great for small game hunting as you keep your eye always on the target.Things I would have changed:Nothing's perfect and that goes for the CO2 Extreme as well. The price is too high given that the Hammerli 850 is of much better quality and less money (without a scope). The scope needs to have AO. The bundled scope is great if you are shooting past 35 yards... unfortunately that is outside of this rifles effective range. Get closer to the advertised 700 FPS. With 14.3 gr Crosman pellets I averaged about 550 give or take. Hobbies topped out at 630 FPS. Lastly, take a lesson from the Hammerli and do something about that spongy trigger.What others should know:I got the best groups at 10 and 20 yards with the Crosman Ultra Magnums. For plinking, target shooting, and even pest control, the CO2 Extreme is a great option inside 20 yards. If you don't want to mess with spring, pump, or PCP, this gives decent power, and very respectable accuracy along with ease of use.

Things I liked:This is an update, I wrote an earlier review and I still think this is a great rifle.Things I would have changed:The Gamo Extreme CO2 has a limitation if you don't use the gun for more than 24 to 48 hours (the limit to whiich you can store the gun with a partially or completely filled CO2 cylinder.) This a real waste of a CO2 Cylinder if you go hunting but once a week. I sent an email to GAMO USA suggesting the following modification.:
Maybe the rifle could be improved by adding a CO2 Cylinder shutoff valve to relieve the gas pressure when not in use. The valve could be closed by an allen wrench accessed through the bottom of the stock. Once the valve is closed the remaining CO2 pressure can be released by removing the magazine and pulling the trigger. This would neutralize any pressure on the trigger CO2 release valve and would keep from wasting CO2 by removing a partially used CO2 Cylinder. The best thing about this modification would be that the gun would always be ready to use just by reopening the CO2 cylinder pressure release valve.

Would be better if gamo set it up to use shotshells also on a rotoryclip to shoot both.i have also a gamo viper also a great gamo gun to own very accurate even with crossman hunting field point lead lots of nockdown power even at 80yds

Things I liked:What a nice CO2 rifle. WOW! Shoots EXTREMEly well. Easy to sight in, accurate. I like everything about it. It was 50 degrees when I sighted in the rifle and I was able to get over 150 shots in. It should not have a problem when used in warmer weather getting 180 to 200 shots per CO2 cyclinder.Things I would have changed:Add rilfe sling mounts.What others should know:I purchased this and when it arrived it appeared to have be used. The pump section for cocking the gun was loose and I had a hard time getting the CO2 cyclinder installed. Rear sight ramp was loose in the bag. The gun would not fire after the first cyclinder was removed and a new one was installed. I returned the rifle to GAMO and they sent me a new one. Great Customer Service! I picked this rifle because I am somewhat disabled and cocking some of the spring loaded rifles is not possible. Check out the videos on YouTube and it shows that this rifle is capable of taking a nice varielty of small game.